James Taylor | Executive | Business Development | Q-Kon | mail me |
In the past two decades or so, numerous projects were successfully completed where VSAT connectivity was required in remote locations such as mines, construction sites, lodges, as well as underserved Point of Sale locations, to name but a few. However, there has always been one common thread: What to do with the end-user access to the satellite network?
These locations typically do not have any on-site LAN or fibre connectivity, so the only viable alternative is a wireless network.
Covering large areas
To cover a large area, it makes sense to deploy a Point-to-Multipoint Fixed Wireless Access (FWA) network with a WiFi overlay as depicted in the diagram below:
To cover ‘smaller’ areas, mesh capable WiFi devices are a quick deployment alternative. Typical use cases are lodges and Point of Sale locations.
The diagram below illustrates such a deployment scenario:
Deploying a WiFi network from a coverage and propagation perspective always poses challenges. Although the laws of physics still apply, the input variables are normally not as exact and predictive.
Propagation prediction programs by most vendors do assist, but on the ground factors such as channel congestion, network congestion, self-interference and external interference is not as predictable.
The launch of 802.11 ax or WiFi 6
The launch of 802.11 ax or WiFi 6 (finally some easier names!) will alleviate many of these issues.
This write-up aims to address some of the advantages and use cases for the networks mentioned above. It also aims to address the specific improvements associated with WiFi 6.
Modulation Scheme Improvements (1024 QAM vs 256 QAM)
Utilising 1024 QAM theoretically provides four times the throughput if combined with the use of 160 MHz channels. A subscriber can now enjoy up to 9.6 Gbps to a single device.
Increased number of sub-channels
Due to the benefits described in the previous point, the number of sub-channels can now also be increased by a factor of four.
Reducing the sub-channel size without compromising performance also adds tremendously to propagation gains.
8×8 DL/UL MU-MIMO
With the advantage of true 8×8 MIMO, this effectively allows up to 8 devices to operate separately on each radio interface. Once again, a four-fold improvement.
Adding the concept of ‘colour’ to the mix
Now we come to a very cool thing: Base Service Station (BSS) colour in WiFi 6. The concept of colour was probably stolen from the fibre people and although this obviously does not refer to different colours as in fibre optics, there is a ‘preamble’ that marks the frames of devices associated to one base station so that it will be ignored by subscribers from another base station.
The diagram below details the ‘isolation’ of say an IoT device network from the general network on site:
Power Saving
With the 4th Industrial Revolution upon us, one of the key criteria of IoT devices and sensors is low power consumption.
WiFi 6 comes to the party in a big way. Transmission time scheduling of devices is now possible. By introducing Target Wake Time (TWT), it allows devices to negotiate when and how often they will wake up to send or receive data, therefore increasing device / sensor battery life.
Putting it all together
If you combine all the advantages of WiFi 6, such as increased coverage, increased performance and speed, more robust interference mitigating technology as well as power saving factors, an HTS VSAT network makes it easier to realise a quickly deployable remote network as described in the beginning.
The diagram below summarises such deployments:
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